From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x227tw1iCZwtABFuWRu1oLNVhmb5zA0oVnMmYJZMLh7nfKSCHGJxjq0Jy4xFAKVAAbh21P4LS ARC-Seal: i=1; a=rsa-sha256; t=1519263345; cv=none; d=google.com; s=arc-20160816; b=ENE9TM/Jm2hNaSq5UOlmoNX54OdlNVCpntHx+rgolpjTKbYcH+HJm9NpB3Adaidcj2 CIU0o9X7PUTt5gSJ1n+KwPVyxneuiimNj8N7ymMX7F/Odc7waWuSc1i+STbfQYZAzVNX z0pK/T/ITsrXjk8EkjwlmXXvBKw16AlZGIKfmQ8SKMtXgxgZ7c792dauKVc7qLWumCGj 8N5KIOLnT0jxLTyo0+NlBkXh3cmGI8VDfedGOobwbOjOTGPBdn66MpC7ifltNBX33aU3 tCo3D4ae54d63mwtA1z4+wWJ9/UQfwHXSRd5df49HuM2cFm4SM4UJ6EIXs2dDb8dVXQP usNA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:references:cc:to:from:subject :delivered-to:list-id:list-subscribe:list-unsubscribe:list-help :list-post:precedence:mailing-list:arc-authentication-results; bh=RtLQ00sMRRLxLpl5Nx34qkWy28XwafRAvmlOVRbfe2E=; b=RSWrmDsypaT+TLBZC0tIZLieZvLWOKLnbzAwDQYAOfSU+eJmlYvwN35G2E7Y9hNsf4 VbvjaDefbxQy9bnYaZMPB0ucDgkZ1At6x02UOkXNcmTgtWYbj65hfqYWIkuAVVF4E+cG IwP3pUe0lCQmegt/TF1QKT2cvBCvR4PTflMVZR8A/fgVNH/vFq7uQUEyV4g7fHLmtDGW rM+jQ4W40t6GSeowZXcNQrxN7vcjddhBk5Wyb6PdkM6/EL66X0OIZndF8CW7ZIOTIPSQ lDod+kB71hbZHrxiU7LsjzYnoDK/z32/EhvMtCjlzwZdowvkMcCUy15lPcmcGYQTjV0D 21Gg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-11882-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-11882-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-11882-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-11882-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: Subject: Re: [PATCH 2/2] arm64: Clear the stack From: Laura Abbott To: Mark Rutland Cc: Alexander Popov , Kees Cook , Ard Biesheuvel , kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20180221011303.20392-1-labbott@redhat.com> <20180221011303.20392-3-labbott@redhat.com> <20180221153850.ywpzsigfnz3etoun@salmiak> <3b76d238-e10a-9abf-c9cb-6d3738eb7896@redhat.com> Message-ID: <572af610-c20f-e826-f124-8df47680795b@redhat.com> Date: Wed, 21 Feb 2018 17:35:24 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <3b76d238-e10a-9abf-c9cb-6d3738eb7896@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1592971106986303834?= X-GMAIL-MSGID: =?utf-8?q?1593063081549325549?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 02/21/2018 03:53 PM, Laura Abbott wrote: >> I *think* this should happen in finish_ret_to_user a few lines down, since we >> can call C code if we branch to work_pending, dirtying the stack. >> > > I think you're right but this didn't immediately work when I tried it. > I'll have to dig into this some more. Okay I figured this out. Not corrupting registers works wonders.